SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea78808156b4f40e803d74c6052a84bdbdd0955a6279811aa5de7049186b94f5' 
  AND token = 'CJMs7OZoECcr8jwjqBpZURarCVl6Uhxu1EbolNjaX7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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