SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bfa3451a08b2037b1673d9c70a6af46fa8b051b39de1e6ea09dba6601ae485e' 
  AND token = '4tzAFEOBibMWiTQ06ozll5lFHaoson8ihFaQB061cj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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