SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1c233f305d94cf8d6185abc75c689bcf2e3afc6c5bb7cb64b92d30984f9bd66' 
  AND token = '1fMw2KSbPMEgA6ytNgMUQ6DGFwE3arpvi3lk55cxMKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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