SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '866d67acbd31b138da7a0afbfdb75d97d714742ca18653677f4b9d5251f12636' 
  AND token = 'xxd3lZUFHPnZMAX2hPRwpkiY7HxoDV/1soqAXz1wBSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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