SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4dfbe81a5277f3e5e4aa1971fad15e6270e721fa98036035e586b5f57a98ef7' 
  AND token = 'rVRYoQyJLTuJVhZ6H6hS2QfiVZWel1RKUrc2FK0cnOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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