SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7e50ece9acd9311592db1c9a53f282ef663408d9b382abf3d703922ae34fe5b' 
  AND token = 'dD1zjIDa1s57wDhrsIpcFFh25Z4fynidMkXspEoEWLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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