SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f801aef5c2f1879f7d9da94e5cbadf3884bd006c20a8ec69d746cccb19a1e031' 
  AND token = 'xeNvOJyAKNLl4CEJ+AMzUAmiK01+waD4AF2LFO6Z3Fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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