SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2db3e111cdac6396cf4b2467ecb4c7d8e3a03827b152d85205f888326137e29' 
  AND token = '9z1RsBCpRzR+bUsK2EmvRT86BpYo+9UJnxWcpsu4j/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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