SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44416f1fc3ab94c74a7e326ab6ec2c4026dc8d71ad19ed688aa928934002d174' 
  AND token = 'VSBgU6dB8tkC5UB81kuVtDClDy257HXHSsXDw0hGcbY=' 
  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"
    }
  }
}