SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02babb2f1c1f914513eb01d305528e26e787691778ddea9ad625bf69715491dd' 
  AND token = 'I7ia9cWPl32Cg9ryV4zdKlp5NkkU1WRce73FWjHAfvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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