SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40fa3622bca00b0c9ce64f4ecc36fcc5efae96f9732869fa3ee0a00ddb85740e' 
  AND token = 'kJ4N45CacnXRCKfdgjDAUJnnfAzgHuEoBMwxAZ3cbzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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