SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da40c3c727fe111e4d0c1a28b0920f760458c4a0fa5a84615e3477a17ded953f' 
  AND token = 'eFDlVvJeaunOJvfNitm+Omf2bIL9Fl5bSHXnpydogR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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