SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c8fcb1499c9669659632869c35d88488c2e6d0c189575c1ff38c98878bbef85' 
  AND token = 'TkbgqnUrVSQBoB2WKLl11qYFxugJWkmygsPBicgBeB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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