SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2547e13c0135928bcad6bd6758b7fd2a2b812547169a43892d1ad7ffc31fbf7a' 
  AND token = 'IPzQbUn3fjDOWCAmarp/hiIlet3ZRy0TczhNnN/4eGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}