SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c910875608c7288908712b8c989672ff38ea148bfc123d1e01f9ad408090e742' 
  AND token = 'hu7bPSK5r9d8q9gSIocmNIn3UA85aBiWWbNFeow1mis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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