SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '149853aabd973afb58d0646554caf76c933b1ea7bdee22f605732fb8352b876c' 
  AND token = 'AYTL+z9asw07Ua7Mjxb7/g+ac6d9xlMja7rubfXoMtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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