SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14d622f77a4128047be6bf2d3c145db47a0424528f125c1ef5db385d88d22075' 
  AND token = '+ofH6puoK40PNBZIQz4RonvhLbb9kdmdZNu6hQiqDME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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