SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ab352ffb44fdcf29770c4739a6e4aa24da8270e5a4280fb552ebfd2e5f26f05' 
  AND token = 'XyxugVhLZ7lbB1h5F4EyIH0qWWTHnRgJDCnWq+K+tRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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