SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8e80ff932605ccd1738dace659f118e82145cf7f05cd7aab16fac1f27adcee5' 
  AND token = 'VumDBdn8HyPI24CM+xwvY59Af2bn+mLesroloKt93dg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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