SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9668b2c7a7042493b9e866e8e82095c7c54bb34ddc8b9100c762897866dabb5c' 
  AND token = 'tjGFNhyOs0jG6wbBMUAvpLvndh+qG8+cPM4EseZIy54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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