SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41c52f09868829bb4cbe6b94658ecb4da3d8ba212283d750b8cc687212bf13cb' 
  AND token = 'nXWMmMYJZ0qoZFLKohBUoueaJYKBCk0kNaAGCBwHoLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}