SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4e6c795de5098555a2afa6957edf60306ec4a2a0e9bbe17a135fb05186ef4c9' 
  AND token = 'kHo/DIozW1VVb7w9KSblzkEC6fxMmp5pthHXiG9sG+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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