SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3432487bfcad73536b2e7d15f902dde5eb524ae8a21d4cbf994b63d15217887' 
  AND token = 'KWArWvDOmj3LPgZuwYrDMdzyTDDj3mRhCiKx32GHo1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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