SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebfa69a7ced33ff31d1ec71a0b2930016fa49269936e1c5eecac418c63f46035' 
  AND token = '3fuWUpCiM0uryTKk0kmsgcTTt2qrKcec6DjhQ1IW42Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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