SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '20d36e889646920b6f4889cd9e8ac0c27d9de16f695636552a9794a288b8dc0e' 
  AND token = 'k3E6uZwP0TZS9I49YuioDshzMdDWB8sBCNhm35berJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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