SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca883783d2ed2a6dd20f60fb0e41a7cf5e0d3b76b1ddc2b2e9090af70ad96f69' 
  AND token = 'nwt9UjADMgbPizX9IAy6lLA+7YxzvlhJr/cBzs/oZ/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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