SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2647ec9c5b306de9973030f319996480175e7d9713bfa268a381d3d479489739' 
  AND token = 'xdv7nnlNkjOTlBr8s9z472qD1YEQYroXcgbx4K6mSYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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