SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f08adc11a5b42e81ba59c6373355279d1399232264b44b065e8220b282d5882' 
  AND token = 'Jl8oRqgMsBZEhosirlk0h4QMrRK2DfTuaCbM6yDnTxs=' 
  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"
    }
  }
}