SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28c654d05515165b908f01264119429c858007c3652c5450858a07b3f7c459f4' 
  AND token = 'ZuFxZOPDyrgMgi59CmuGxQNb40pAXgxVUoka5mCVeOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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