SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1eddb82efe0d36a6fad5753fb4124e2c8f9caae6dee5b0d51a8cc2b62f6c244' 
  AND token = 'sqGOMvrQ7sRr5lPNTvhKpREkJlzvODiPr6AvhzMGSco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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