SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '267fb13ba8680d916b73151a79dcacecabe14a9553a114dad781091a963ff448' 
  AND token = 'HkPR+PiVkAtRsqzzgS0BJ6VBcqdnLHhWT6y1BoyLC/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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