SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8b07dd78cae30f566db349267f56b75fbc8f7b9cfaa36437eec4bc0557d9ff1' 
  AND token = 'Ql3/8BkoK2RaUMBZS+6j+nlYHJlv3XI8NVZr0riHyrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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