SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3aad1c4ff0d4322f6f6dc279c352407044121e5bc7d2c496fed08b9ce24c08fc' 
  AND token = 'CtsCPLqgjYO8q7uIfPZ9vconA+v6XMuSI8p0FgBBDHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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