SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b611d942919fd5a3bdc4ad908e91cd8a1d3fe9f51cd0692284c173f28f2dea6c' 
  AND token = 'A2jKOcYuXrmeClLIBQ3FXgUydkn4eID/Ef35HWAyz64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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