SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4002f826097d1fb520ed81b393d66702e8c146045b69b356c00c615621c9e5d3' 
  AND token = 'bawuMaQ+gsSKw6dv/x1fvuaBMQMl3EFin2/oDzHoin8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}