SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a7e28d7234605e4e0248c4f66fac5cff72f2255ab328d526f739a844000e074' 
  AND token = 'AzQaDDS+RbGITdYmogV6YXoaGX9DwuLedwpiS2j37QQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}