SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7ff098089df5fe43605fc776efbd69fd26f7b0b884365f6ef1bce0db5f036f7' 
  AND token = 'n5GoVv2Nd5MPErjlavg/0hfJr5y0/Iv9+dnENds2TlE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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