SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7903f348ae499ee82272b7a0ce787ebe359d46de1555acfd61a5c1af5b02785f' 
  AND token = 'Y6gQI7QWC1KTb65dGVSHp5cXZmnnHASY/VJEynrhN7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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