SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '34d4e37faec517677f5ce6aa1ff2002da0f6fcde1e9cdc425cc904880a12ace0' 
  AND token = 'S21IUlGau/ix9HiPVS7RyzPy1pgkDV6RwvG/1j8Y9BM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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