SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6433db826e12ad4b578ebfbcca3ee11412108c9b221d81729c024b27b6539c0' 
  AND token = 'bF+a2xnTewq5qi0BUZPULIhsYHgUVZu5ZVBUU4WQOLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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