SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e43561c37f61709ff07ead014cb2591b6f33e3cb9a1476f75756069ad509d173' 
  AND token = 'Jih2SpYEWU/vkp/SqykYpj4SU1KfUHyP+Od9874pZJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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