SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66f3ad0765ee74ce0e73f8512a3a2e629ff1c9bd874191ddd900df18d827793e' 
  AND token = 'WKzQ6SNXOQmAFJ7ii3z8+n8HCPzTnXR20yS1pMcNA68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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