SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f478c9c521576fd044aa80e7de83dd0adcfa83360310c0667b9bd2c41a919fc' 
  AND token = '8Mwqi7FCmXhDdeT+K9YztiqozZcWU9xd5R1EjiqwXi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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