SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '711a391c53f556b2679ac19c54996fe0151d52322bd4013000fe3efcee2e3795' 
  AND token = 's04417vVAfnBQYZDqyA/HR0gMkSUNURXuSEpNlle23E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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