SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d92a9dd2101e4ae42f7642c86e9e9fda8cf0755853501bc1daa06d49a3f82bf' 
  AND token = 'BdTH+YlIGFweOyDeHI/sirvfZon5kC1bllWXFJ66hos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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