SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0590e211da9c84bc929c0b8f1b61c9facb9583419700686801a6d6710b87aa35' 
  AND token = 'KTwE8vjVk/CPzegYGCNC1bCMuDdVw9haOfej2d8vpxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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