SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18f61a3828e95c08965508cb7e5b35574ae7a7c527172bb282025967bf103792' 
  AND token = 'gVcvoWSYjPslxbT61rcsFdFQGpuLAeRoMuaPkajMvJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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