SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '63c4a11e3f8b9e5b0583d07c2628a22d657f8c4fc900f18efbc8e9fd5b087c58' 
  AND token = 'yktT7n37A/QhwXnl+ChykoDss/N7BSxGogVYATGQqhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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