SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9900fb1b47a875d6379a1fb85648ef91e391d324a1f673e5dc8849c2cf65774' 
  AND token = 'rot/vsl9tqurfbYUToyI5Okc0IHkP23dwJTetFuV+jE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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