SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9071a67db38dd04b202ebe5746ff604e4949f043ef6a00eab76ad079b5873019' 
  AND token = 'wp3+1BwUjfuhRGLHTFzIcPN3zm8hIDAgYB9gckO5rBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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