SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a5cfc229ac4af41df48c90a19ac6ca7df6f2d81037924b3eee75a1facbab396' 
  AND token = 'lpM9GxnfVqX7oFjasRAYwuzaAnSuI24ofm4zuWkVTn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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