SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f9cefee6bff7add26ac5a367dae3de3a4b019ce607366a6fae71d302c1731b7' 
  AND token = 'XvEKSTzZA/hqSoQBGponcHFbxwbp+wAG0IMv7qZwjDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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