SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59b583fea35d186842376f87d6273bec6f7676a9c9efbcd901bca30503c4e517' 
  AND token = 'cYuiLoFhQiYPQeDSsGwdPomju4YU4dq+M5c/KLUt2K0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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