SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0368591267eab651347ce8e410dc922eac821f6776dd1c822e029dd349fa9b87' 
  AND token = '5A2DZ7V4MJuzX35nTcK6AJuEXzwDv6bR3naYb5IBXUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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