SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '792698c5e9577d00985d200f7393cd0d4bd107b77aa22905b7e613f0068cb1e4' 
  AND token = '/4oNBSVRMFFjWHwim/SMNzn07Zfzs/irGrnFTCe+iFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}