SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '250cc056d6cd3a4de83b4b45de7ff68074730ec01f96fd62bc2af8a624ddf5d6' 
  AND token = 'VjIjYlRX2eKfNBiHAkRWynVhJwddj8eG2ztvmFysYVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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