SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ab0b2cc76bda1c4c56d13ba1e75d00800995b13688e7699e9b0855525ed8aa7' 
  AND token = 'sZKTVFePt/mAAB0Djg/cgvhYtm1M4VRvd9zMCtZA8pQ=' 
  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"
    }
  }
}