SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16cf3ce2c07c009bdabff7b960d82b1bf5a5a42d3feb98f6a86cd176e3817311' 
  AND token = 'SNPHljkH90YmwpJdunFQbjGNvn7CSqgis7Rh+GHWhU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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