SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4111d05cce1c5f51daeb328f417e59b2c3e0156dd46c3088ea23f15672ffb92' 
  AND token = 'ioX/2rqfxtCZDpfRNfzZbKC9DFXvo1PHv/dA6tpWdDg=' 
  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"
    }
  }
}