SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c3af1412013c26081f314395f8ca89992acc226a2a86bb195425efc323f02ac' 
  AND token = 'v7suBYWnmyg6XtaTbenmefaUDqVWsIBLiJYYJOD4K28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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