SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '042e1de30156e7c39aacc63374e809e57cbff9eda5e62bb1acccae551f559c02' 
  AND token = 'Ir2pcKagVFMoiet2O9WSVXrUyxsaBRRMnlTcIgZ/4S0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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