SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be292208b2c0af21dab0b08302497dd61b2d20401c1d1c36b6a54037f26480b1' 
  AND token = 'EWKQ2LNiupN81ojaDsT7uhErDh21KnRduHYP5fKcn0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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