SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '971afa4cb195646236cb36c02597140861d351218fa8fd05b96a47978248322e' 
  AND token = 'EyljF11WsLAlntzlkMqhbxDQLnJJ9Z2q07AJcQqmh6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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