SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd38fb0a6ba7a18ebd8ad52cb16613eeb9438b3500e0388bdb5037f0924adb2b2' 
  AND token = 'apQBhnHri/vd+K9lGT8cmF+lE07eBaZBrEVDV2O/KGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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