SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5793f756ae0f1516fea81e32af1ac7e6b90fefa23f3cf9a62f5925f2903918b' 
  AND token = 'GWDgqRaxbjoUPsg+vZJuHfmEc/qju+ha9TnWI8+qfcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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