SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d3cbd8f9826a965cd82bab0a088a7c2317699ee7c2353f14fc156ce1f4c1e5b' 
  AND token = 'mFmSpNpnUpO3pxMlyo+JhHi4Zlz2gouT1lFKhvdaIkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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