SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf737ed18bc1f263352f0da3c6bff8c22a8b12289e69a062a53e889198ace68c' 
  AND token = 'kWwOvArhgEbLU1o2jqUqTED1hkUDNUntox1ccxj0O8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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