SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b891277dbf1b88c3516c2a0233a7d6bd9410aff6a45847a35720b02f15373dc' 
  AND token = 'KvQ1MNICEg5CjhAjEF3Po022VZRvJslHyIRNz8dUTWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}