SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '482b680363b9e6d65b325511ea1bb8443e17cb14ca1f696883b196ae557fc8d7' 
  AND token = 'PC1K/4bu4wjYOn4vWNh06+3dcfRYGhmpp0o+l+jhVRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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