SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e024ac27a3917f8ba478ab0949c59d14704ec8649b0f131253f0971da8ff82e' 
  AND token = 'G1AI+KQiFzEf8gY6DMPHv6hGK/ALMsIJSatM4HXw5DQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}