SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47ffbbc0d2e30bccb52a2d0fbcee131271a47053a76c0cb54e69bf3ee72dc617' 
  AND token = '+fMKFn/5O9ufC+LzWmelIyBMqZMbed3wzAh1Pqs2P1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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