SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab7323e9f87e1605de0022c5951650627819d24d7172b98b4ded4a95c8a08bf4' 
  AND token = 'qctyUtXu+sF6calUhLHzXpHhGDz/t0Tm3Z/ml++Rm2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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