SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbfc9364d1695f7a6826b0cf2255d1d046654190022713e107388a8a4ad39150' 
  AND token = 'fHBUQqHFDi39mAFg2y0ieHObQKz9ZcVOCyYdWYNeWCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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