SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed42c26321a9a1e86d17565fcfed92881edc7d7848f6ba5273026b4575590826' 
  AND token = 'gCLQT7TFvQfIsksOxoJDQjKU/l/0SL+JyZXJ17TeKfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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