SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bb858f4f09469aa914038b4ab4c95e4d5cc1cdb7bdf47eac7d2217d4616a878' 
  AND token = 'ckwUsqI5R4OjPn/PXGuon8Ep7GfcbiFmtgdIwv/knHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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