SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc3374d7964f5f77340f3ca2390f0d81dfdea766ab430bf45fc026ac94fb1ccc' 
  AND token = 'yd3Lv58IsO4izMnXuIFcbHkV5y2HEmoH3Nmug551rok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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