SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f1bca2704d83fdc4ae437eb88e5fa07081d3527c5cff577d4f270be24724c25' 
  AND token = '93zpn6kASYEEVEQH6oaeUDRr1h0Y3hApdYnTfoTCeSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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