SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c0598766d0986bc534358874f553ba48b83e0fb37d7f698eee8785e441f15b5' 
  AND token = 'BsKawI6Gj1GnmFrvbHbqOvc+I0fkUNarYrSmULMGXh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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