SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93a5e81a79355695d8f3f094f514bf22b148fbc9ab52762d5bc9cb78861b8225' 
  AND token = 'Hi0b35eGPUCUEmd0WPfUdwLHEugOodHvsf2MU38zuy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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