SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b0317c1e7f4d24934099d15c7bd8eeba63f2de8196669d95d2b22b6635363e8' 
  AND token = 'tT+45cafYM2bdLcrNI7i8WWF9e9uGoNCv9n+1Db7wX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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