SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb28646d39874affac0a2b1da6580ffbdea3e534ac940672323ff9b16f47685b' 
  AND token = 'zdNi1AetbQNir+v+gkiMtmxGS60ztTh7ycmwl7/zVZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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