SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1c1546340678004c06c324286a8e360b47c750a206fdee64729ba6d61c247f9' 
  AND token = 'kpZJkwAV7YeaFDROeF7Tvy3LJ/iZTd9K7uixgX7fuoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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