SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3f214cc1167865b19c770bc49ae14313c3e620a0d7da1aeca4ade8f16eb2bcac' 
  AND token = '5eVeRUzqiPa3zI2MzqbzGZvwCyM2zsFqguCon8R63cA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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