SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7063b080f449a889203892cdedc8779c4da7c2033f5483325c846ba82afc3fe5' 
  AND token = '8h+pKADXyB5o/qVcz2aUdvJwq0wzjKqGMBgXZicg8oo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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