SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daab8b7489649feffe28553dc62dca8afff86d6ee65d4213407fbf765a019dec' 
  AND token = 'stzUOuwVbNKblnhGXWTIDET8iuHMWu2S23uL59lQMKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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