SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '462d8963f81ec1a8e4e1bdca1819b02a93f69752d3183139e847d96a02222dc5' 
  AND token = 'LChssgreEn2AugUHbqfWp8DU1dTUhPU5ojbCsrJSDfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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