SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '396f1c3382f0863851da07431226661c48060ab53177f74bb44afe59794a8752' 
  AND token = 'LzrdhSeOO4xZgrExdxdfU4TcvJ6rqwpB0AkNBITR0ww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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