SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bd4b790eaa143125e38c57a131f39d1053dfd27375ae63ae897f86cfa1eaff6' 
  AND token = 'F3Sh29rXMGb56/BKElv+anBQhUIdpicQ4Pbofd43t2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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