SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7f5dbcb3c8e582aca7a8392d067482f29213796dbeceb4f201c027ddc78561e' 
  AND token = 'jGF96MGZAOOliBIOXrNyiWZj2EReg5DmmztadI4JGco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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