SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f2aadac196dffc4d25152ac7c23f7106ee8f1a62177d42fdca51010cacc48e93' 
  AND token = 'D/9UWMKTr5XS2gkDd7UlFhozMBhak205NmdwmSt49p0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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