SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3571e9d6462a7cfafb694994524a790ac60808510dcde6bfe491b20e88c7571' 
  AND token = 'hx38/5Ea5okolaQueGcyDxkVpX10JWqikR5NPsv9GTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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