SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae4a06e87c2fc8c885d94a444e290c639ff8bfb477facd477406a0e6f7a31929' 
  AND token = 'vAeF7WYzqCzltQGhDWNqVEbmD+J8vUOwMCWexAIGRCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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