SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e331f70fa7a91adf28c0b825d4b4fdc6a39f3c4106a79a20fb5ba44dbf8d810c' 
  AND token = 'IA8WEmCoLQsoviL4uUqO2XY6zAY0ShtGkEUXRIdnOSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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