SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '749b329ac4a1a1930f248eefa70abd6f902dcdb6451d7543fff9264786d55c05' 
  AND token = 'qUwtTnEK3ZnIl/wC2lMZcjkizVq+t3EV3LVsBI2ujiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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