SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54aa383df45a134ec2aef1a9edd65e618806e73f47419ad5aba3340710504630' 
  AND token = '7VT0YWLGrQ6AjGCgobdmftL9uKWNHHnO3gcksmkP0XQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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