SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50c7eb3f45cc8c57876f8e931b4b201b1355551825070b32c74c16d4da854f34' 
  AND token = 'L3a4xZqfHS/4J0/QJO0LfXfIWw/TpwojJkFJcclJtsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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