SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13c45ab6a3e80c9ef9cb0375cdf21364bbfbf81fd8064c9bd199dde7cac5b6bb' 
  AND token = 'y2f3GKJPeVwpx40v6rkd4NrkMHgM5RtmllBogxiwSpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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