SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea7644d952434c3221874b141e685b2a110821dcf9bcc823c30e0f5e80c619b1' 
  AND token = 'KkD4ekqByYL7FD8v6xDhPEjWXH4Qc0JVY6IgZQ4U+oM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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