SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbbe30fbc9a6b399a90cfc37eb7f31cb5150da6710711ff57386fecf95004308' 
  AND token = 'h3psNeVKsym7YcvNHjy0HOnPnlCaUR1/xZHazAFQ88c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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