SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f567c2f4ea7985adf65843a82f745e9fcba8680aff45fb5f80b62ff0a5b269cb' 
  AND token = '1GkbJzedmoxz/HPMloeN8gMiSGVK8vLOc0o9BxbK0RA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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