SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '827186fafb4edccfcf530a72b182b4cfbb852e1d9dae5d1f71c31eb536b5992a' 
  AND token = 'HtgixQwXg+t2Vl9F2z71hK3pp8JnU3v43aXBLWU7m+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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