SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb7d5f523fddd5e34f306b732739118a05a2892f57aaaaadbedf85528ef33a46' 
  AND token = '3nh2/h3tG/FToRgTtUF9+W66oaQg2qhMhAVmhkTAl2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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